K8S MySql配置映射-只读文件系统

Question

我试图用kubernetes configmap和PV、PVC传递mysql配置，但我遇到了错误。

chown: /var/lib/mysql/..data: Read-only file system
chown: /var/lib/mysql/crud.sql: Read-only file system
chown: /var/lib/mysql/..2021_12_29_12_32_17.053559530: Read-only file system
chown: /var/lib/mysql/..2021_12_29_12_32_17.053559530: Read-only file system
chown: /var/lib/mysql/: Read-only file system
chown: /var/lib/mysql/: Read-only file system

如果im不是initContainers，则使用im获取错误：

2021-12-29 12:49:05+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.27-1debian10 started.
chown: changing ownership of '/var/lib/mysql/': Read-only file system
chown: changing ownership of '/var/lib/mysql/..data': Read-only file system
chown: changing ownership of '/var/lib/mysql/crud.sql': Read-only file system
chown: changing ownership of '/var/lib/mysql/..2021_12_29_12_43_00.339135384': Read-only file system
chown: changing ownership of '/var/lib/mysql/..2021_12_29_12_43_00.339135384/crud.sql': Read-only file system

部署.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
name: {{ .Values.deployment.mysql.name }}
namespace: {{ .Values.namespace }}
spec:
selector:
matchLabels:
app: {{ .Values.deployment.mysql.name }}
strategy:
type: Recreate
template:
metadata:
labels:
app: {{ .Values.deployment.mysql.name }}
spec:
# initContainers:
# - name: chmod-er
#   image: busybox:latest
#   command:
#   - /bin/chown
#   - -R
#   - "999:999" 
#   - /var/lib/mysql
#   volumeMounts:
#   - name: cm2
#     mountPath: /var/lib/mysql
containers:
- image: {{ .Values.deployment.mysql.image }}
name: {{ .Values.deployment.mysql.name }}
securityContext:
runAsUser: 0
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom: 
secretKeyRef:
name: mysql-secret
key: mysql-root-password
ports:
- containerPort: {{ .Values.deployment.mysql.port }}
name: {{ .Values.deployment.mysql.name }} 
volumeMounts:
- name: cm2
mountPath: /var/lib/mysql/
readOnly: false
volumes:
- name: mysqlvolume
persistentVolumeClaim:
claimName: mysqlvolume
readOnly: false
- name: cm2
configMap:
name: cm2

正如你所看到的，我尝试了initContainers，但仍然得到了相同的错误。

pv.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
name: mysqlvolume
spec:
accessModes:
- ReadWriteOnce
capacity:
storage: 1Gi
hostPath:
path: C:Usersib151w.minikubevolume

pvc.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mysqlvolume
namespace: {{ .Values.namespace }}
namespace: app
spec:
storageClassName: standard
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 50Mi

configmap.yaml

apiVersion: v1
data:
crud.sql: |-
/*!40101 SET NAMES utf8 */;
/*!40014 SET FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET SQL_NOTES=0 */;
CREATE DATABASE /*!32312 IF NOT EXISTS*/ crud /*!40100 DEFAULT CHARACTER SET utf8mb4 */;
USE crud;
DROP TABLE IF EXISTS books;
CREATE TABLE `books` (
`id` int NOT NULL AUTO_INCREMENT,
`first_name` varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
`last_name` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
`email` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
`phone` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
`department` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
`manager` varchar(50) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
`created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
kind: ConfigMap
metadata:
creationTimestamp: "2021-12-29T10:24:41Z"
name: cm2
namespace: app
resourceVersion: "6526"
uid: 31ab7ef8-94a4-41d3-af19-ddfceb04e124

我只是想在pod启动时将这个配置传递给它，所以mysql pod将与我想要的数据库在一起。

Answer 1

您正在装载configMap(cm2(，k8s将configMap作为只读装载。您的意思是在/var/lib/mysql/下安装mysqlvolume，在其他地方安装cm2吗？Mysql/var/lib/mysql是Mysql写入tablespace数据的数据目录，而不是安装configMap的地方

如果是：

volumeMounts:
- name: cm2
- mountPath: /var/lib/mysql/

应将其更改为

volumeMounts:
- name: mysqlvolume
- mountPath: /var/lib/mysql/
volumeMounts:
- name: cm2
- mountPath: ~/db_scripts ( or any other path)

您还需要在容器上执行命令mysql < ~/db_scripts/crud.sql来创建表。